Study on salinity tolerance and allelic diversity of microsatellite markers associated with salinity in Iranian wheat genotypes

In order to evaluate allelic diversity of microsatellite markers in QTL regions associated with salinity tolerance and to assess relatedness of these markers with yield performance of Iranian wheats under normal and salt stress conditions, twenty-five wheat genotypes (comprising tolerant and sensitive Iranian landraces, commercial cultivars and breeding lines), were studied using 45 microsatellite primers. Results of yield mean comparison showed that there were significant differences among genotypes in both environmental conditions. Under stress conditions, genotypes no 25 (Pishtaz/Karchia) and 16 (Sissons/3/Alvd//Aldan/Ias58) had the highest and lowest grain yields, respectively. Based on grain yield mean under both stress and non-stress conditions as well as tolerance and susceptibility indices, the genotypes were classified into tolerant, moderately tolerant and sensitive groups. From 45 microsatellite primer pairs used, 27 markers were polymorphic. In total, these markers generated 95 alleles, from which 89 alleles were polymorphic, possessing 2-7 alleles with the average of 3.52 alleles per locus. The polymorphic information content (PIC) varied from 0.077 to 0.454 with the average of 0.258 and the Marker Index (MI) ranged from 0.151 to 1.19 with the average of 0.79 for different primers. Cluster analysis based on molecular data, could completely separate sensitive and tolerant genotypes and relatively was concordant with grouping of genotypes based on field results. Principal coordinate analysis (PCOA), mostly confirmed the results of cluster analysis. Results of molecular data demonstrated that SSR markers: gwm291, gpw345, wmc249, barc353.1, cfa2170.2, gwm339 and wmc326 had higher PIC & MI values and can be considered as suitable microsatellite markers to assess the genetic diversity among the wheat genotypes in salinity stress breeding programs.